Medical devices in contact with, or implanted within, the human body can facilitate transmission of microbial pathogens into the body and cause infections in patients that are the recipients of such medical devices. When an infection occurs, it may result in serious health complications for the patient and require a variety of additional treatment regimens including antibiotics, and even the need for additional surgeries to remove the infected device and/or tissue surrounding the device.
Several strategies can be employed to help prevent microbial colonization and infection of medically implanted devices, including systemic administration of antibiotics and coating devices with antiseptic creams and gels. Another approach is to coat the devices with an antibiotic-impregnated coating which can extend the antimicrobial lifetime beyond that of antiseptic creams, and concentrate the activity directly at the site of implantation. The activity of such an antimicrobial coating is highly dependent on the sustained release of therapeutic levels of the antimicrobial agent. Several factors can influence the rate of release of these agents including the local environment (i.e., temperature, pH) and chemistry of the antimicrobial coating material itself (i.e., cross-link density, porosity, water permeability, etc.).